#include <stdio.h>

int main() 
{
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	if(a+b<=c||a+c<=b||b+c<=a)
		printf("non-triangle.\n");
	else if(a==b&&b==c)
		printf("equilateral triangle.\n");
	else if(a==b||a==c||c==b)
		printf("isoceles triangle.\n");
	else printf("triangle.\n");
	
}